This article tells you what your electronics manufacturing service providers need you to prepare an accurate quote for a typical printed circuit board assembly project.
Contract electronics manufacturing services or EMS suppliers generally work with customers in a wide range of industries with different requirements for inventory control, testing, product packaging and product support. In some applications, the EMS provider simply mounts the printed circuit boards and sends the cards to the customer. In other applications, the EMS electronics manufacturing service provider will mount the printed circuit board, load firmware / software into memory, test the board, and then mount the board and cables, cabinets, and associated documentation on a finished product that is shipped to the client.
Some customers will provide all of the materials, slabs and electronic components needed for a job, and the EMS provider will assemble the printed circuit boards, perform the required tests, and ship the customer ready cards. This is generally considered as stock provided on a consignment basis in which the EMS provider basically provides manpower and experience only. Some clients are part of the materials, such as specialty or high-cost integrated circuits, proprietary parts such as transformers or coils, printed circuit boards, etc. and rely on the EMS provider to purchase the rest of the components needed to assemble the system.
Most providers of electronic manufacturing services prefer their own purchasing power, their extensive contacts, and existing parts shares, where applicable, to provide all the materials needed for a specific client project. This method is generally considered as inventory provided on a turn-key basis.
But, before that happens, the EMS provider must provide a quote from the board or a price estimate mounted to the client for the project. In addition to quantity commitments, production release quantity and annual usage quantity, this pricing process also requires a detailed list of customer materials along with a set of Gerber files for the printed circuit boards. The BOM should define all components together with the approved supplier and the vendor part number for each component. This information enables the Materials Management group to determine the availability, packaging, and pricing of each component based on quantities and vendor information. BOM information is also required to enable a technical review to determine the amount of labor and the equipment needed to place the parts and weld the components to the plate.